114 MODEL AVIATION
THIS COLUMN IS about electric glider winches and glider-winch
sources. For the newbies’ benefit, I’ll provide a basic description of a
glider winch. Experienced readers may want to skip ahead to where I
cover some winch-design issues and include a list of American gliderwinch
suppliers.
The glider winch is widely used for contests and “serious” sport
flying. In a nutshell, the winch is an electric motor that reels line onto a
cylinder (called a drum). The winch assembly is set up (hopefully) on
the downwind side of the field.
Mike Garton, 2733 NE 95th Ave., Ankeny IA 50021; E-mail: [email protected]
RADIO CONTROL SOARING
Winch from Tim McCann kit. Motor, solenoids, switches are
purchased separate. His Web site has plans, parts list.
Contents of the McCann WN 2.0 winch kit. These are the parts
that would be difficult for most people to make.
This is a McCann turnaround pulley. The design has the ability to
let tow rings and parachutes pass through it.
Winch built from Mike Wade parts. Bicycle-hub antireverse
mechanism prevents backlash. Brake stops kiting when used.
The line runs from the winch drum, along the ground in the upwind
direction, through a pulley staked to the ground (called a
“turnaround”), and back downwind to the winch location where it is
hooked to the glider. A pilot uses a foot switch to pulse the motor,
forcing the line to tow the glider into the wind. The line’s stretchiness
smoothes the forces transmitted to the glider.
Unlike with hi-starts, winch operators can vary the line tension
without changing the glider’s elevator position. Small and large gliders
can be launched with the same winch. Gentle line tension is needed for
small/weak/slow gliders.
Skill is required to launch a weak glider gently on a winch. Pilots
must learn to tap the winch pedal slowly but regularly while
adapting to the model’s needs. Moderate tensions are used for large
gliders. Low-drag, strong gliders can benefit from an increase in
tension late in the launch to slingshot off the end of the line (a zoom
launch).
Also unlike a hi-start, a pilot can abort a winch launch by getting
off the foot switch, thus decreasing and eventually eliminating the
line tension. This often saves a glider when something goes seriously
wrong.
Any control failure caused by the receiver switch off, dying
receiver battery, or radio interference on a hi-start can cause a nasty
crash accelerated by the energy of the rubber tubing. Another
advantage of the winch is that it adapts easily to different field sizes
without cutting lines.
Is the winch for everyone? No. Cost and field-setup hassle are
major disadvantages. A winch’s parts alone will run you at least a
couple hundred dollars, even if you have the tools, knowledge, and
skills to build it yourself. Completed systems range from
approximately $500 to $1,200 without the 12-volt battery and the
battery charger.
Setting up a winch and taking it down is no fun. The motor alone
weighs close to 20 pounds. Complete full-size winches start at roughly
23 pounds, plus the 12-volt, lead-acid car battery. Well-thought-out
designs have a handle built into the winch frame roughly above its
center of mass.
It helps greatly if your flying field allows vehicles to drive on it
while setting up winches. This is usually not an option at sod farms.
Winch owners often make carts or dollys to drag winches to their
May 2004 115
The Little BIG Winch from Walt Dimick is much easier to lug
around and less expensive than the competing designs.
Ultimate Turnaround made by Walt
Dimick. The pulley is up on a stake, which
lessens wear on the line in rough fields.
A Winch Doctor winch, which is available as a kit or assembled. The Winch Doctor has
excellent winch maintenance tips on his Web site.
A Real Balls retrofit ball-bearing endplate for the winch motors.
Notice the cooling fins and grease fitting.
Other end of the Real Balls on a Ford long-shaft starter motor.
One experiment showed a 20% reduction in current draw.
location on the downwind side of the field.
There is a nice article about a hand truck
converted into a winch and retriever cart on
the Quiet Flyer Web site.
The Little BIG Winch (LBW) partially
alleviates the cost and weight issues. At 16
pounds plus battery, the LBW and the
recommended small tractor battery are easier
to set up and put away than a full-size winch.
It is also at the low end of the winch price
range.
The LBW is lighter and smaller because it
uses a special permanent magnet motor on a
small frame. It can launch big gliders and
even zoom-launch them. The design was
intended to be a convenient winch for
personal practice use. The LBW is not
designed for the nonstop, all-day use that a
winch would be put through at a contest. Walt
Dimick—who makes the LBW—also makes
a nice anodized turnaround and other
specialty glider products. Check out his Web
site.
The Ford Long Shaft Starter Motor has
been the standard winch motor in the US for
decades. It is popular because it is easy to
mount a drum on the 5.75-inch shaft
protruding from the motor. (See the picture.)
The “hot” winches use 6-volt Ford Long
Shafts—part 3110—run at 12 volts. Tamer
winches use 12-volt motors—part 3115—run
at 12 volts. Reconditioned 3110 motors have
been getting scarce. The (dog) sport of lure
coursing has created a new motor built to the
same specification. The bunny is pulled by a
device similar to our winches.
Winches are difficult to build from
scratch. The winch drums are usually
machined from aluminum on a metal lathe.
Most winch frames are made from pieces of
square steel welded together. Unless you have
access to machine-shop tools, you must
purchase the metal parts from one of the
vendors I will list or have them custom
machined (more expensive yet).
Another reason why winch building is not
for everyone is the winch motor’s high current
demand. Douglass Boyd, aka the Winch
Doctor, says, “Using a clamp-on ammeter,
I’ve seen spikes of 600 amps; average launch
is 120-200 amps.” This explains the use of
welding cables to run from the battery to the
winch.
It is nontrivial to reliably switch that much
current. Winches use a foot switch connected
to a solenoid or two solenoids in series. The
solenoid’s purpose is to open and close the
electrical contacts on the high-current circuit.
Most designs use two solenoids to allow safe
operation even when one fails. A caveat is
that two solenoids will only delay a failure
unless you regularly test them to learn when
one has gone bad. Replacing the solenoids
every year or two is another option.
A solenoid failure on a winch usually
means that the contacts weld themselves
together and the winch sticks on. A method to
quickly cut power to the winch in an
emergency is required. This emergency
disconnect can be as simple as a pull-out
connector as shown on the assembled
McCann winch. A large knife-style switch is
another option.
I have seen solenoid failures a couple
times in the last 20 years of flying. The pilot
usually does not think fast enough to save a
wooden glider. If the pilot is lucky, a helper
will be alert and close enough to pull the
emergency power switch. If the pilot cannot
get the model off the runaway line quickly,
the wings generally fail and then the fuselage
is strained through the turnaround.
There are other safety issues when using a
winch. Keep hands and loose clothing away
from moving parts. The moving line will act
like a band saw if it slides across a person. Go
to the Winch Doctor’s Web site for an
excellent article about winch safety.
I cannot say enough about the Winch
Doctor’s contributions to the art of building
and maintaining winches. His Web site
features super articles about the differences in
motors and maintaining winch brushes.
The Winch Doctor makes Real Balls;
these machined aluminum endplates
include ball bearings (the standard starter
motor has bushings), grease fittings for the
bearings, cooling fins, and mounting lugs.
These are overengineered, cost-is-noobject
pieces of hardware, and I love them.
The Real Balls are said to reduce current
draw 20% and will make the starter motor
last much longer. The Winch Doctor also
sells nice winch kits, complete winches,
116 MODEL AVIATION
and other glider specialty products.
Tim McCann (who makes landing skegs
for gliders) is a winch vendor with a nice,
informative Web site. I particularly like its
freely downloadable winch plans, which are
complete with instructions, a parts list, parts
sources, a wiring diagram, and an assembly
drawing. The plans show his frame and drum,
of course.
Laser Arts also has winch plans available.
The Laser Arts plans set is a thick stack of
paper. A great deal of CAD work obviously
went into them. I have always thought that
Dave Meyers of Laser Arts needs to team up
with a frame and drum manufacturer to make
the winch design practical. Laser Arts now
sells plans for a retriever too.
Vince Botkin sells winches, winch kits,
and retrievers. Retrievers hold a spool of light
line that can bring the end of the winch line
back to the winch. Vince sells one large-spool
(20 inches) retriever design and is currently
working on a small-spool design.
I do not have any pictures of Vince’s
products, but you can see them on his Web
site. The frames are square steel tubing that is
welded together, ground smooth, and powder
coated. Real Balls kits will fit on the frame.
Vince’s complete winches are the least
expensive of the full-size types listed here.
Mike Wade is the fourth winch-parts
source I found. He built the winches that
118 MODEL AVIATION
AMA has been using at the Nationals for
years. He sells frames, drums (with or without
brakes), and turnarounds.
Most people buy their winch lines from
Memphis Net and Twine. The product is
White Braided Nylon Seine Twine. The 170-
or 200-pound test is good for a personal
winch, and the 250- or 290-pound test is
frequently used at contests. MA
Sources:
Winch Doctor (Real Balls, winches, winch
kits, winch parts, maintenance articles):
Douglass Boyd
4130 SW 117th Ave PMB #168
Beaverton OR 97005
[email protected]
www.monkeytumble.com/winchdoc/
Botkin Designs (winches, winch kit, retriever):
31071 Christine Ln.
Nuevo CA 92567
(909) 928-0956
http://hometown.aol.com/botkindesigns/
Walt Dimick (Little Big Winch, Ultimate
Turnaround):
12724 SE 22nd Ave.
Milwaukie OR 97222
(503) 659-7883
www.irfmachineworks.com/lbwinch/
Tom Copp/Composite Specialties (F3B
winch):
2195 Canyon Dr #D
Costa Mesa CA 92627
(949) 645-7032
www.f3x.com/f3bstuff/f3bwinch.htm
Laser Arts (winch, retriever plans):
www.laserartco.com/
Launch truck article:
www.quietflyer.com/ (click on “Online
Articles”)
Superskeg.com (winches, winch kits,
turnarounds):
Tim McCann
Box 2091
Harrison AR 72602
(870) 365-0023
www.superskeg.com/
Injoy Lure Coursing (new 3110 winch
motors):
(802) 425-3691
www.injoy-1.com
Mike Wade (winch parts):
[email protected]
Memphis Net and Twine (braided-nylon
winch line):
www.memphisnet.net
Edition: Model Aviation - 2004/05
Page Numbers: 114,115,116,118
Edition: Model Aviation - 2004/05
Page Numbers: 114,115,116,118
114 MODEL AVIATION
THIS COLUMN IS about electric glider winches and glider-winch
sources. For the newbies’ benefit, I’ll provide a basic description of a
glider winch. Experienced readers may want to skip ahead to where I
cover some winch-design issues and include a list of American gliderwinch
suppliers.
The glider winch is widely used for contests and “serious” sport
flying. In a nutshell, the winch is an electric motor that reels line onto a
cylinder (called a drum). The winch assembly is set up (hopefully) on
the downwind side of the field.
Mike Garton, 2733 NE 95th Ave., Ankeny IA 50021; E-mail: [email protected]
RADIO CONTROL SOARING
Winch from Tim McCann kit. Motor, solenoids, switches are
purchased separate. His Web site has plans, parts list.
Contents of the McCann WN 2.0 winch kit. These are the parts
that would be difficult for most people to make.
This is a McCann turnaround pulley. The design has the ability to
let tow rings and parachutes pass through it.
Winch built from Mike Wade parts. Bicycle-hub antireverse
mechanism prevents backlash. Brake stops kiting when used.
The line runs from the winch drum, along the ground in the upwind
direction, through a pulley staked to the ground (called a
“turnaround”), and back downwind to the winch location where it is
hooked to the glider. A pilot uses a foot switch to pulse the motor,
forcing the line to tow the glider into the wind. The line’s stretchiness
smoothes the forces transmitted to the glider.
Unlike with hi-starts, winch operators can vary the line tension
without changing the glider’s elevator position. Small and large gliders
can be launched with the same winch. Gentle line tension is needed for
small/weak/slow gliders.
Skill is required to launch a weak glider gently on a winch. Pilots
must learn to tap the winch pedal slowly but regularly while
adapting to the model’s needs. Moderate tensions are used for large
gliders. Low-drag, strong gliders can benefit from an increase in
tension late in the launch to slingshot off the end of the line (a zoom
launch).
Also unlike a hi-start, a pilot can abort a winch launch by getting
off the foot switch, thus decreasing and eventually eliminating the
line tension. This often saves a glider when something goes seriously
wrong.
Any control failure caused by the receiver switch off, dying
receiver battery, or radio interference on a hi-start can cause a nasty
crash accelerated by the energy of the rubber tubing. Another
advantage of the winch is that it adapts easily to different field sizes
without cutting lines.
Is the winch for everyone? No. Cost and field-setup hassle are
major disadvantages. A winch’s parts alone will run you at least a
couple hundred dollars, even if you have the tools, knowledge, and
skills to build it yourself. Completed systems range from
approximately $500 to $1,200 without the 12-volt battery and the
battery charger.
Setting up a winch and taking it down is no fun. The motor alone
weighs close to 20 pounds. Complete full-size winches start at roughly
23 pounds, plus the 12-volt, lead-acid car battery. Well-thought-out
designs have a handle built into the winch frame roughly above its
center of mass.
It helps greatly if your flying field allows vehicles to drive on it
while setting up winches. This is usually not an option at sod farms.
Winch owners often make carts or dollys to drag winches to their
May 2004 115
The Little BIG Winch from Walt Dimick is much easier to lug
around and less expensive than the competing designs.
Ultimate Turnaround made by Walt
Dimick. The pulley is up on a stake, which
lessens wear on the line in rough fields.
A Winch Doctor winch, which is available as a kit or assembled. The Winch Doctor has
excellent winch maintenance tips on his Web site.
A Real Balls retrofit ball-bearing endplate for the winch motors.
Notice the cooling fins and grease fitting.
Other end of the Real Balls on a Ford long-shaft starter motor.
One experiment showed a 20% reduction in current draw.
location on the downwind side of the field.
There is a nice article about a hand truck
converted into a winch and retriever cart on
the Quiet Flyer Web site.
The Little BIG Winch (LBW) partially
alleviates the cost and weight issues. At 16
pounds plus battery, the LBW and the
recommended small tractor battery are easier
to set up and put away than a full-size winch.
It is also at the low end of the winch price
range.
The LBW is lighter and smaller because it
uses a special permanent magnet motor on a
small frame. It can launch big gliders and
even zoom-launch them. The design was
intended to be a convenient winch for
personal practice use. The LBW is not
designed for the nonstop, all-day use that a
winch would be put through at a contest. Walt
Dimick—who makes the LBW—also makes
a nice anodized turnaround and other
specialty glider products. Check out his Web
site.
The Ford Long Shaft Starter Motor has
been the standard winch motor in the US for
decades. It is popular because it is easy to
mount a drum on the 5.75-inch shaft
protruding from the motor. (See the picture.)
The “hot” winches use 6-volt Ford Long
Shafts—part 3110—run at 12 volts. Tamer
winches use 12-volt motors—part 3115—run
at 12 volts. Reconditioned 3110 motors have
been getting scarce. The (dog) sport of lure
coursing has created a new motor built to the
same specification. The bunny is pulled by a
device similar to our winches.
Winches are difficult to build from
scratch. The winch drums are usually
machined from aluminum on a metal lathe.
Most winch frames are made from pieces of
square steel welded together. Unless you have
access to machine-shop tools, you must
purchase the metal parts from one of the
vendors I will list or have them custom
machined (more expensive yet).
Another reason why winch building is not
for everyone is the winch motor’s high current
demand. Douglass Boyd, aka the Winch
Doctor, says, “Using a clamp-on ammeter,
I’ve seen spikes of 600 amps; average launch
is 120-200 amps.” This explains the use of
welding cables to run from the battery to the
winch.
It is nontrivial to reliably switch that much
current. Winches use a foot switch connected
to a solenoid or two solenoids in series. The
solenoid’s purpose is to open and close the
electrical contacts on the high-current circuit.
Most designs use two solenoids to allow safe
operation even when one fails. A caveat is
that two solenoids will only delay a failure
unless you regularly test them to learn when
one has gone bad. Replacing the solenoids
every year or two is another option.
A solenoid failure on a winch usually
means that the contacts weld themselves
together and the winch sticks on. A method to
quickly cut power to the winch in an
emergency is required. This emergency
disconnect can be as simple as a pull-out
connector as shown on the assembled
McCann winch. A large knife-style switch is
another option.
I have seen solenoid failures a couple
times in the last 20 years of flying. The pilot
usually does not think fast enough to save a
wooden glider. If the pilot is lucky, a helper
will be alert and close enough to pull the
emergency power switch. If the pilot cannot
get the model off the runaway line quickly,
the wings generally fail and then the fuselage
is strained through the turnaround.
There are other safety issues when using a
winch. Keep hands and loose clothing away
from moving parts. The moving line will act
like a band saw if it slides across a person. Go
to the Winch Doctor’s Web site for an
excellent article about winch safety.
I cannot say enough about the Winch
Doctor’s contributions to the art of building
and maintaining winches. His Web site
features super articles about the differences in
motors and maintaining winch brushes.
The Winch Doctor makes Real Balls;
these machined aluminum endplates
include ball bearings (the standard starter
motor has bushings), grease fittings for the
bearings, cooling fins, and mounting lugs.
These are overengineered, cost-is-noobject
pieces of hardware, and I love them.
The Real Balls are said to reduce current
draw 20% and will make the starter motor
last much longer. The Winch Doctor also
sells nice winch kits, complete winches,
116 MODEL AVIATION
and other glider specialty products.
Tim McCann (who makes landing skegs
for gliders) is a winch vendor with a nice,
informative Web site. I particularly like its
freely downloadable winch plans, which are
complete with instructions, a parts list, parts
sources, a wiring diagram, and an assembly
drawing. The plans show his frame and drum,
of course.
Laser Arts also has winch plans available.
The Laser Arts plans set is a thick stack of
paper. A great deal of CAD work obviously
went into them. I have always thought that
Dave Meyers of Laser Arts needs to team up
with a frame and drum manufacturer to make
the winch design practical. Laser Arts now
sells plans for a retriever too.
Vince Botkin sells winches, winch kits,
and retrievers. Retrievers hold a spool of light
line that can bring the end of the winch line
back to the winch. Vince sells one large-spool
(20 inches) retriever design and is currently
working on a small-spool design.
I do not have any pictures of Vince’s
products, but you can see them on his Web
site. The frames are square steel tubing that is
welded together, ground smooth, and powder
coated. Real Balls kits will fit on the frame.
Vince’s complete winches are the least
expensive of the full-size types listed here.
Mike Wade is the fourth winch-parts
source I found. He built the winches that
118 MODEL AVIATION
AMA has been using at the Nationals for
years. He sells frames, drums (with or without
brakes), and turnarounds.
Most people buy their winch lines from
Memphis Net and Twine. The product is
White Braided Nylon Seine Twine. The 170-
or 200-pound test is good for a personal
winch, and the 250- or 290-pound test is
frequently used at contests. MA
Sources:
Winch Doctor (Real Balls, winches, winch
kits, winch parts, maintenance articles):
Douglass Boyd
4130 SW 117th Ave PMB #168
Beaverton OR 97005
[email protected]
www.monkeytumble.com/winchdoc/
Botkin Designs (winches, winch kit, retriever):
31071 Christine Ln.
Nuevo CA 92567
(909) 928-0956
http://hometown.aol.com/botkindesigns/
Walt Dimick (Little Big Winch, Ultimate
Turnaround):
12724 SE 22nd Ave.
Milwaukie OR 97222
(503) 659-7883
www.irfmachineworks.com/lbwinch/
Tom Copp/Composite Specialties (F3B
winch):
2195 Canyon Dr #D
Costa Mesa CA 92627
(949) 645-7032
www.f3x.com/f3bstuff/f3bwinch.htm
Laser Arts (winch, retriever plans):
www.laserartco.com/
Launch truck article:
www.quietflyer.com/ (click on “Online
Articles”)
Superskeg.com (winches, winch kits,
turnarounds):
Tim McCann
Box 2091
Harrison AR 72602
(870) 365-0023
www.superskeg.com/
Injoy Lure Coursing (new 3110 winch
motors):
(802) 425-3691
www.injoy-1.com
Mike Wade (winch parts):
[email protected]
Memphis Net and Twine (braided-nylon
winch line):
www.memphisnet.net
Edition: Model Aviation - 2004/05
Page Numbers: 114,115,116,118
114 MODEL AVIATION
THIS COLUMN IS about electric glider winches and glider-winch
sources. For the newbies’ benefit, I’ll provide a basic description of a
glider winch. Experienced readers may want to skip ahead to where I
cover some winch-design issues and include a list of American gliderwinch
suppliers.
The glider winch is widely used for contests and “serious” sport
flying. In a nutshell, the winch is an electric motor that reels line onto a
cylinder (called a drum). The winch assembly is set up (hopefully) on
the downwind side of the field.
Mike Garton, 2733 NE 95th Ave., Ankeny IA 50021; E-mail: [email protected]
RADIO CONTROL SOARING
Winch from Tim McCann kit. Motor, solenoids, switches are
purchased separate. His Web site has plans, parts list.
Contents of the McCann WN 2.0 winch kit. These are the parts
that would be difficult for most people to make.
This is a McCann turnaround pulley. The design has the ability to
let tow rings and parachutes pass through it.
Winch built from Mike Wade parts. Bicycle-hub antireverse
mechanism prevents backlash. Brake stops kiting when used.
The line runs from the winch drum, along the ground in the upwind
direction, through a pulley staked to the ground (called a
“turnaround”), and back downwind to the winch location where it is
hooked to the glider. A pilot uses a foot switch to pulse the motor,
forcing the line to tow the glider into the wind. The line’s stretchiness
smoothes the forces transmitted to the glider.
Unlike with hi-starts, winch operators can vary the line tension
without changing the glider’s elevator position. Small and large gliders
can be launched with the same winch. Gentle line tension is needed for
small/weak/slow gliders.
Skill is required to launch a weak glider gently on a winch. Pilots
must learn to tap the winch pedal slowly but regularly while
adapting to the model’s needs. Moderate tensions are used for large
gliders. Low-drag, strong gliders can benefit from an increase in
tension late in the launch to slingshot off the end of the line (a zoom
launch).
Also unlike a hi-start, a pilot can abort a winch launch by getting
off the foot switch, thus decreasing and eventually eliminating the
line tension. This often saves a glider when something goes seriously
wrong.
Any control failure caused by the receiver switch off, dying
receiver battery, or radio interference on a hi-start can cause a nasty
crash accelerated by the energy of the rubber tubing. Another
advantage of the winch is that it adapts easily to different field sizes
without cutting lines.
Is the winch for everyone? No. Cost and field-setup hassle are
major disadvantages. A winch’s parts alone will run you at least a
couple hundred dollars, even if you have the tools, knowledge, and
skills to build it yourself. Completed systems range from
approximately $500 to $1,200 without the 12-volt battery and the
battery charger.
Setting up a winch and taking it down is no fun. The motor alone
weighs close to 20 pounds. Complete full-size winches start at roughly
23 pounds, plus the 12-volt, lead-acid car battery. Well-thought-out
designs have a handle built into the winch frame roughly above its
center of mass.
It helps greatly if your flying field allows vehicles to drive on it
while setting up winches. This is usually not an option at sod farms.
Winch owners often make carts or dollys to drag winches to their
May 2004 115
The Little BIG Winch from Walt Dimick is much easier to lug
around and less expensive than the competing designs.
Ultimate Turnaround made by Walt
Dimick. The pulley is up on a stake, which
lessens wear on the line in rough fields.
A Winch Doctor winch, which is available as a kit or assembled. The Winch Doctor has
excellent winch maintenance tips on his Web site.
A Real Balls retrofit ball-bearing endplate for the winch motors.
Notice the cooling fins and grease fitting.
Other end of the Real Balls on a Ford long-shaft starter motor.
One experiment showed a 20% reduction in current draw.
location on the downwind side of the field.
There is a nice article about a hand truck
converted into a winch and retriever cart on
the Quiet Flyer Web site.
The Little BIG Winch (LBW) partially
alleviates the cost and weight issues. At 16
pounds plus battery, the LBW and the
recommended small tractor battery are easier
to set up and put away than a full-size winch.
It is also at the low end of the winch price
range.
The LBW is lighter and smaller because it
uses a special permanent magnet motor on a
small frame. It can launch big gliders and
even zoom-launch them. The design was
intended to be a convenient winch for
personal practice use. The LBW is not
designed for the nonstop, all-day use that a
winch would be put through at a contest. Walt
Dimick—who makes the LBW—also makes
a nice anodized turnaround and other
specialty glider products. Check out his Web
site.
The Ford Long Shaft Starter Motor has
been the standard winch motor in the US for
decades. It is popular because it is easy to
mount a drum on the 5.75-inch shaft
protruding from the motor. (See the picture.)
The “hot” winches use 6-volt Ford Long
Shafts—part 3110—run at 12 volts. Tamer
winches use 12-volt motors—part 3115—run
at 12 volts. Reconditioned 3110 motors have
been getting scarce. The (dog) sport of lure
coursing has created a new motor built to the
same specification. The bunny is pulled by a
device similar to our winches.
Winches are difficult to build from
scratch. The winch drums are usually
machined from aluminum on a metal lathe.
Most winch frames are made from pieces of
square steel welded together. Unless you have
access to machine-shop tools, you must
purchase the metal parts from one of the
vendors I will list or have them custom
machined (more expensive yet).
Another reason why winch building is not
for everyone is the winch motor’s high current
demand. Douglass Boyd, aka the Winch
Doctor, says, “Using a clamp-on ammeter,
I’ve seen spikes of 600 amps; average launch
is 120-200 amps.” This explains the use of
welding cables to run from the battery to the
winch.
It is nontrivial to reliably switch that much
current. Winches use a foot switch connected
to a solenoid or two solenoids in series. The
solenoid’s purpose is to open and close the
electrical contacts on the high-current circuit.
Most designs use two solenoids to allow safe
operation even when one fails. A caveat is
that two solenoids will only delay a failure
unless you regularly test them to learn when
one has gone bad. Replacing the solenoids
every year or two is another option.
A solenoid failure on a winch usually
means that the contacts weld themselves
together and the winch sticks on. A method to
quickly cut power to the winch in an
emergency is required. This emergency
disconnect can be as simple as a pull-out
connector as shown on the assembled
McCann winch. A large knife-style switch is
another option.
I have seen solenoid failures a couple
times in the last 20 years of flying. The pilot
usually does not think fast enough to save a
wooden glider. If the pilot is lucky, a helper
will be alert and close enough to pull the
emergency power switch. If the pilot cannot
get the model off the runaway line quickly,
the wings generally fail and then the fuselage
is strained through the turnaround.
There are other safety issues when using a
winch. Keep hands and loose clothing away
from moving parts. The moving line will act
like a band saw if it slides across a person. Go
to the Winch Doctor’s Web site for an
excellent article about winch safety.
I cannot say enough about the Winch
Doctor’s contributions to the art of building
and maintaining winches. His Web site
features super articles about the differences in
motors and maintaining winch brushes.
The Winch Doctor makes Real Balls;
these machined aluminum endplates
include ball bearings (the standard starter
motor has bushings), grease fittings for the
bearings, cooling fins, and mounting lugs.
These are overengineered, cost-is-noobject
pieces of hardware, and I love them.
The Real Balls are said to reduce current
draw 20% and will make the starter motor
last much longer. The Winch Doctor also
sells nice winch kits, complete winches,
116 MODEL AVIATION
and other glider specialty products.
Tim McCann (who makes landing skegs
for gliders) is a winch vendor with a nice,
informative Web site. I particularly like its
freely downloadable winch plans, which are
complete with instructions, a parts list, parts
sources, a wiring diagram, and an assembly
drawing. The plans show his frame and drum,
of course.
Laser Arts also has winch plans available.
The Laser Arts plans set is a thick stack of
paper. A great deal of CAD work obviously
went into them. I have always thought that
Dave Meyers of Laser Arts needs to team up
with a frame and drum manufacturer to make
the winch design practical. Laser Arts now
sells plans for a retriever too.
Vince Botkin sells winches, winch kits,
and retrievers. Retrievers hold a spool of light
line that can bring the end of the winch line
back to the winch. Vince sells one large-spool
(20 inches) retriever design and is currently
working on a small-spool design.
I do not have any pictures of Vince’s
products, but you can see them on his Web
site. The frames are square steel tubing that is
welded together, ground smooth, and powder
coated. Real Balls kits will fit on the frame.
Vince’s complete winches are the least
expensive of the full-size types listed here.
Mike Wade is the fourth winch-parts
source I found. He built the winches that
118 MODEL AVIATION
AMA has been using at the Nationals for
years. He sells frames, drums (with or without
brakes), and turnarounds.
Most people buy their winch lines from
Memphis Net and Twine. The product is
White Braided Nylon Seine Twine. The 170-
or 200-pound test is good for a personal
winch, and the 250- or 290-pound test is
frequently used at contests. MA
Sources:
Winch Doctor (Real Balls, winches, winch
kits, winch parts, maintenance articles):
Douglass Boyd
4130 SW 117th Ave PMB #168
Beaverton OR 97005
[email protected]
www.monkeytumble.com/winchdoc/
Botkin Designs (winches, winch kit, retriever):
31071 Christine Ln.
Nuevo CA 92567
(909) 928-0956
http://hometown.aol.com/botkindesigns/
Walt Dimick (Little Big Winch, Ultimate
Turnaround):
12724 SE 22nd Ave.
Milwaukie OR 97222
(503) 659-7883
www.irfmachineworks.com/lbwinch/
Tom Copp/Composite Specialties (F3B
winch):
2195 Canyon Dr #D
Costa Mesa CA 92627
(949) 645-7032
www.f3x.com/f3bstuff/f3bwinch.htm
Laser Arts (winch, retriever plans):
www.laserartco.com/
Launch truck article:
www.quietflyer.com/ (click on “Online
Articles”)
Superskeg.com (winches, winch kits,
turnarounds):
Tim McCann
Box 2091
Harrison AR 72602
(870) 365-0023
www.superskeg.com/
Injoy Lure Coursing (new 3110 winch
motors):
(802) 425-3691
www.injoy-1.com
Mike Wade (winch parts):
[email protected]
Memphis Net and Twine (braided-nylon
winch line):
www.memphisnet.net
Edition: Model Aviation - 2004/05
Page Numbers: 114,115,116,118
114 MODEL AVIATION
THIS COLUMN IS about electric glider winches and glider-winch
sources. For the newbies’ benefit, I’ll provide a basic description of a
glider winch. Experienced readers may want to skip ahead to where I
cover some winch-design issues and include a list of American gliderwinch
suppliers.
The glider winch is widely used for contests and “serious” sport
flying. In a nutshell, the winch is an electric motor that reels line onto a
cylinder (called a drum). The winch assembly is set up (hopefully) on
the downwind side of the field.
Mike Garton, 2733 NE 95th Ave., Ankeny IA 50021; E-mail: [email protected]
RADIO CONTROL SOARING
Winch from Tim McCann kit. Motor, solenoids, switches are
purchased separate. His Web site has plans, parts list.
Contents of the McCann WN 2.0 winch kit. These are the parts
that would be difficult for most people to make.
This is a McCann turnaround pulley. The design has the ability to
let tow rings and parachutes pass through it.
Winch built from Mike Wade parts. Bicycle-hub antireverse
mechanism prevents backlash. Brake stops kiting when used.
The line runs from the winch drum, along the ground in the upwind
direction, through a pulley staked to the ground (called a
“turnaround”), and back downwind to the winch location where it is
hooked to the glider. A pilot uses a foot switch to pulse the motor,
forcing the line to tow the glider into the wind. The line’s stretchiness
smoothes the forces transmitted to the glider.
Unlike with hi-starts, winch operators can vary the line tension
without changing the glider’s elevator position. Small and large gliders
can be launched with the same winch. Gentle line tension is needed for
small/weak/slow gliders.
Skill is required to launch a weak glider gently on a winch. Pilots
must learn to tap the winch pedal slowly but regularly while
adapting to the model’s needs. Moderate tensions are used for large
gliders. Low-drag, strong gliders can benefit from an increase in
tension late in the launch to slingshot off the end of the line (a zoom
launch).
Also unlike a hi-start, a pilot can abort a winch launch by getting
off the foot switch, thus decreasing and eventually eliminating the
line tension. This often saves a glider when something goes seriously
wrong.
Any control failure caused by the receiver switch off, dying
receiver battery, or radio interference on a hi-start can cause a nasty
crash accelerated by the energy of the rubber tubing. Another
advantage of the winch is that it adapts easily to different field sizes
without cutting lines.
Is the winch for everyone? No. Cost and field-setup hassle are
major disadvantages. A winch’s parts alone will run you at least a
couple hundred dollars, even if you have the tools, knowledge, and
skills to build it yourself. Completed systems range from
approximately $500 to $1,200 without the 12-volt battery and the
battery charger.
Setting up a winch and taking it down is no fun. The motor alone
weighs close to 20 pounds. Complete full-size winches start at roughly
23 pounds, plus the 12-volt, lead-acid car battery. Well-thought-out
designs have a handle built into the winch frame roughly above its
center of mass.
It helps greatly if your flying field allows vehicles to drive on it
while setting up winches. This is usually not an option at sod farms.
Winch owners often make carts or dollys to drag winches to their
May 2004 115
The Little BIG Winch from Walt Dimick is much easier to lug
around and less expensive than the competing designs.
Ultimate Turnaround made by Walt
Dimick. The pulley is up on a stake, which
lessens wear on the line in rough fields.
A Winch Doctor winch, which is available as a kit or assembled. The Winch Doctor has
excellent winch maintenance tips on his Web site.
A Real Balls retrofit ball-bearing endplate for the winch motors.
Notice the cooling fins and grease fitting.
Other end of the Real Balls on a Ford long-shaft starter motor.
One experiment showed a 20% reduction in current draw.
location on the downwind side of the field.
There is a nice article about a hand truck
converted into a winch and retriever cart on
the Quiet Flyer Web site.
The Little BIG Winch (LBW) partially
alleviates the cost and weight issues. At 16
pounds plus battery, the LBW and the
recommended small tractor battery are easier
to set up and put away than a full-size winch.
It is also at the low end of the winch price
range.
The LBW is lighter and smaller because it
uses a special permanent magnet motor on a
small frame. It can launch big gliders and
even zoom-launch them. The design was
intended to be a convenient winch for
personal practice use. The LBW is not
designed for the nonstop, all-day use that a
winch would be put through at a contest. Walt
Dimick—who makes the LBW—also makes
a nice anodized turnaround and other
specialty glider products. Check out his Web
site.
The Ford Long Shaft Starter Motor has
been the standard winch motor in the US for
decades. It is popular because it is easy to
mount a drum on the 5.75-inch shaft
protruding from the motor. (See the picture.)
The “hot” winches use 6-volt Ford Long
Shafts—part 3110—run at 12 volts. Tamer
winches use 12-volt motors—part 3115—run
at 12 volts. Reconditioned 3110 motors have
been getting scarce. The (dog) sport of lure
coursing has created a new motor built to the
same specification. The bunny is pulled by a
device similar to our winches.
Winches are difficult to build from
scratch. The winch drums are usually
machined from aluminum on a metal lathe.
Most winch frames are made from pieces of
square steel welded together. Unless you have
access to machine-shop tools, you must
purchase the metal parts from one of the
vendors I will list or have them custom
machined (more expensive yet).
Another reason why winch building is not
for everyone is the winch motor’s high current
demand. Douglass Boyd, aka the Winch
Doctor, says, “Using a clamp-on ammeter,
I’ve seen spikes of 600 amps; average launch
is 120-200 amps.” This explains the use of
welding cables to run from the battery to the
winch.
It is nontrivial to reliably switch that much
current. Winches use a foot switch connected
to a solenoid or two solenoids in series. The
solenoid’s purpose is to open and close the
electrical contacts on the high-current circuit.
Most designs use two solenoids to allow safe
operation even when one fails. A caveat is
that two solenoids will only delay a failure
unless you regularly test them to learn when
one has gone bad. Replacing the solenoids
every year or two is another option.
A solenoid failure on a winch usually
means that the contacts weld themselves
together and the winch sticks on. A method to
quickly cut power to the winch in an
emergency is required. This emergency
disconnect can be as simple as a pull-out
connector as shown on the assembled
McCann winch. A large knife-style switch is
another option.
I have seen solenoid failures a couple
times in the last 20 years of flying. The pilot
usually does not think fast enough to save a
wooden glider. If the pilot is lucky, a helper
will be alert and close enough to pull the
emergency power switch. If the pilot cannot
get the model off the runaway line quickly,
the wings generally fail and then the fuselage
is strained through the turnaround.
There are other safety issues when using a
winch. Keep hands and loose clothing away
from moving parts. The moving line will act
like a band saw if it slides across a person. Go
to the Winch Doctor’s Web site for an
excellent article about winch safety.
I cannot say enough about the Winch
Doctor’s contributions to the art of building
and maintaining winches. His Web site
features super articles about the differences in
motors and maintaining winch brushes.
The Winch Doctor makes Real Balls;
these machined aluminum endplates
include ball bearings (the standard starter
motor has bushings), grease fittings for the
bearings, cooling fins, and mounting lugs.
These are overengineered, cost-is-noobject
pieces of hardware, and I love them.
The Real Balls are said to reduce current
draw 20% and will make the starter motor
last much longer. The Winch Doctor also
sells nice winch kits, complete winches,
116 MODEL AVIATION
and other glider specialty products.
Tim McCann (who makes landing skegs
for gliders) is a winch vendor with a nice,
informative Web site. I particularly like its
freely downloadable winch plans, which are
complete with instructions, a parts list, parts
sources, a wiring diagram, and an assembly
drawing. The plans show his frame and drum,
of course.
Laser Arts also has winch plans available.
The Laser Arts plans set is a thick stack of
paper. A great deal of CAD work obviously
went into them. I have always thought that
Dave Meyers of Laser Arts needs to team up
with a frame and drum manufacturer to make
the winch design practical. Laser Arts now
sells plans for a retriever too.
Vince Botkin sells winches, winch kits,
and retrievers. Retrievers hold a spool of light
line that can bring the end of the winch line
back to the winch. Vince sells one large-spool
(20 inches) retriever design and is currently
working on a small-spool design.
I do not have any pictures of Vince’s
products, but you can see them on his Web
site. The frames are square steel tubing that is
welded together, ground smooth, and powder
coated. Real Balls kits will fit on the frame.
Vince’s complete winches are the least
expensive of the full-size types listed here.
Mike Wade is the fourth winch-parts
source I found. He built the winches that
118 MODEL AVIATION
AMA has been using at the Nationals for
years. He sells frames, drums (with or without
brakes), and turnarounds.
Most people buy their winch lines from
Memphis Net and Twine. The product is
White Braided Nylon Seine Twine. The 170-
or 200-pound test is good for a personal
winch, and the 250- or 290-pound test is
frequently used at contests. MA
Sources:
Winch Doctor (Real Balls, winches, winch
kits, winch parts, maintenance articles):
Douglass Boyd
4130 SW 117th Ave PMB #168
Beaverton OR 97005
[email protected]
www.monkeytumble.com/winchdoc/
Botkin Designs (winches, winch kit, retriever):
31071 Christine Ln.
Nuevo CA 92567
(909) 928-0956
http://hometown.aol.com/botkindesigns/
Walt Dimick (Little Big Winch, Ultimate
Turnaround):
12724 SE 22nd Ave.
Milwaukie OR 97222
(503) 659-7883
www.irfmachineworks.com/lbwinch/
Tom Copp/Composite Specialties (F3B
winch):
2195 Canyon Dr #D
Costa Mesa CA 92627
(949) 645-7032
www.f3x.com/f3bstuff/f3bwinch.htm
Laser Arts (winch, retriever plans):
www.laserartco.com/
Launch truck article:
www.quietflyer.com/ (click on “Online
Articles”)
Superskeg.com (winches, winch kits,
turnarounds):
Tim McCann
Box 2091
Harrison AR 72602
(870) 365-0023
www.superskeg.com/
Injoy Lure Coursing (new 3110 winch
motors):
(802) 425-3691
www.injoy-1.com
Mike Wade (winch parts):
[email protected]
Memphis Net and Twine (braided-nylon
winch line):
www.memphisnet.net
